diff --git a/src/Teams.php b/src/Teams.php
index 341d851..6630b20 100644
--- a/src/Teams.php
+++ b/src/Teams.php
@@ -11,13 +11,6 @@ class Teams
      */
     public static function concat(Team ...$args/*variable arguments*/): array
     {
-        $result = [];
-
-        foreach ($args as $currentTeam) {
-            $localCurrentTeam = $currentTeam;
-            $result[] = $localCurrentTeam;
-        }
-
-        return $result;
+        return $args;
     }
 }
diff --git a/tests/GameInfoTest.php b/tests/GameInfoTest.php
index f84ea24..621af32 100644
--- a/tests/GameInfoTest.php
+++ b/tests/GameInfoTest.php
@@ -5,7 +5,7 @@ declare(strict_types=1);
 namespace DNW\Skills\Tests;
 
 use DNW\Skills\GameInfo;
-use \DNW\Skills\Rating;
+use DNW\Skills\Rating;
 use PHPUnit\Framework\TestCase;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\UsesClass;
diff --git a/tests/PlayerTest.php b/tests/PlayerTest.php
index b6f6461..82092be 100644
--- a/tests/PlayerTest.php
+++ b/tests/PlayerTest.php
@@ -10,7 +10,6 @@ use PHPUnit\Framework\TestCase;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\UsesClass;
 
-
 #[CoversClass(Player::class)]
 #[UsesClass(Guard::class)]
 class PlayerTest extends TestCase
diff --git a/tests/RatingContainerTest.php b/tests/RatingContainerTest.php
new file mode 100644
index 0000000..d93e564
--- /dev/null
+++ b/tests/RatingContainerTest.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DNW\Skills\Tests;
+
+use DNW\Skills\RatingContainer;
+use DNW\Skills\HashMap;
+use DNW\Skills\Player;
+use DNW\Skills\Rating;
+use DNW\Skills\Guard;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\UsesClass;
+
+#[CoversClass(RatingContainer::class)]
+#[UsesClass(Hashmap::class)]
+#[UsesClass(Player::class)]
+#[UsesClass(Rating::class)]
+#[UsesClass(Guard::class)]
+class RatingContainerTest extends TestCase
+{
+    public function testRatingContainer(): void
+    {
+        $rc = new RatingContainer();
+
+        $this->assertEquals([], $rc->getAllPlayers());
+        $this->assertEquals([], $rc->getAllRatings());
+        $this->assertEquals(0, $rc->count());
+
+        $p1 = new Player(1);
+        $p2 = new Player(2);
+
+        $r1 = new Rating(100, 10);
+        $r2 = new Rating(200, 20);
+
+        $rc->setRating($p1, $r1);
+        $rc->setRating($p2, $r2);
+
+        $this->assertEquals($r1, $rc->getRating($p1));
+        $this->assertEquals($r2, $rc->getRating($p2));
+
+        $this->assertEquals([$p1, $p2], $rc->getAllPlayers());
+        $this->assertEquals([$r1, $r2], $rc->getAllRatings());
+        $this->assertEquals(2, $rc->count());
+    }
+}
diff --git a/tests/TeamTest.php b/tests/TeamTest.php
new file mode 100644
index 0000000..62770cf
--- /dev/null
+++ b/tests/TeamTest.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DNW\Skills\Tests;
+
+use DNW\Skills\Team;
+use DNW\Skills\RatingContainer;
+use DNW\Skills\HashMap;
+use DNW\Skills\Player;
+use DNW\Skills\Rating;
+use DNW\Skills\Guard;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\UsesClass;
+
+#[CoversClass(Team::class)]
+#[CoversClass(RatingContainer::class)]
+#[UsesClass(Hashmap::class)]
+#[UsesClass(Player::class)]
+#[UsesClass(Rating::class)]
+#[UsesClass(Guard::class)]
+class TeamTest extends TestCase
+{
+    public function testTeam(): void
+    {
+        $p1 = new Player(1);
+        $p2 = new Player(2);
+
+        $r1 = new Rating(100, 10);
+        $r2 = new Rating(200, 20);
+
+        $rc = new Team($p1, $r1);
+
+        $this->assertEquals($r1, $rc->getRating($p1));
+        $this->assertEquals([$p1], $rc->getAllPlayers());
+        $this->assertEquals([$r1], $rc->getAllRatings());
+        $this->assertEquals(1, $rc->count());
+
+        $rc->addPlayer($p2, $r2);
+
+        $this->assertEquals($r2, $rc->getRating($p2));
+
+        $this->assertEquals([$p1, $p2], $rc->getAllPlayers());
+        $this->assertEquals([$r1, $r2], $rc->getAllRatings());
+        $this->assertEquals(2, $rc->count());
+    }
+
+    public function testTeamConstructor(): void
+    {
+        $p = new Player(0);
+        $r = new Rating(100, 10);
+
+        $rc = new Team(NULL, NULL);
+        $this->assertEquals(0, $rc->count());
+
+        $rc = new Team($p, NULL);
+        $this->assertEquals(0, $rc->count());
+
+        $rc = new Team(NULL, $r);
+        $this->assertEquals(0, $rc->count());
+
+        $rc = new Team($p, $r);
+        $this->assertEquals($r, $rc->getRating($p));
+        $this->assertEquals([$p], $rc->getAllPlayers());
+        $this->assertEquals([$r], $rc->getAllRatings());
+        $this->assertEquals(1, $rc->count());
+    }
+}
diff --git a/tests/TeamsTest.php b/tests/TeamsTest.php
new file mode 100644
index 0000000..fcb0ba7
--- /dev/null
+++ b/tests/TeamsTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DNW\Skills\Tests;
+
+use DNW\Skills\Teams;
+use DNW\Skills\Team;
+use DNW\Skills\RatingContainer;
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\UsesClass;
+
+#[CoversClass(Teams::class)]
+#[UsesClass(Team::class)]
+#[UsesClass(RatingContainer::class)]
+class TeamsTest extends TestCase
+{
+    public function testTeamsConcat(): void
+    {
+        $t1 = new Team();
+        $t2 = new Team();
+        $t3 = new Team();
+
+        $this->assertEquals([$t1], Teams::concat($t1));
+        $this->assertEquals([$t1, $t2, $t3], Teams::concat($t1, $t2, $t3));
+    }
+}